
How To Figure Out What Size Air Conditioner You Need – According to the American Society of Heating, Refrigerating and Air Conditioning Engineers (ASHRAE), the standard height is 3 meters; 1.0 met = 58.2 W/m² (18.4 Btu/h·ft²), which is equal to the energy produced per unit surface area of an average sitting human at rest. The average human has a surface area of 1.8 m² (19 ft²); If we use 1.35 as the average metabolic rate for common activities such as sitting, standing, sleeping, writing, walking; Based on ANSI/ASHRAE Standard 55-2017, Thermal Environmental Conditions for Human Life.
In the Philippines, the traditional way to express the size of an air conditioning unit would be “HP or Horsepower” and “TR or Tons of Cooling”. However, DOE recommends selecting/purchasing an air conditioning unit based on Cooling Capacity expressed in kilojoules per hour (kJ/hour), kilowatts (kW), or British Thermal Units per hour (Btu/hour), as this is a more precise measurement. How much cold air the air conditioning unit can deliver in one hour.
How To Figure Out What Size Air Conditioner You Need
To further explain, a 2 HP air conditioning unit from Company X and a 2 HP air conditioning unit from Company Y may have different cold air delivery rates (Cooling Capacity). Therefore, it would be better to use the Cooling Capacity (kJ/hour, kW or Btu/hour) when determining the appropriate unit for your space.
Is My Air Conditioner Too Big For My Home
Calculator provides results in kJ/hour, kW and BTU/hour; so consumers can easily determine the cooling capacity on the product nameplate in any unit of measurement used.
When purchasing an air conditioning unit, choose one with the same or slightly higher cooling capacity as calculated in the Air Conditioner Size Calculator. A slightly higher cooling capacity can provide the additional coolness needed, especially in dry or summer seasons.
Consumers can check the product nameplate located on the side or back of the unit or the DOE Energy Label located on the unit to determine the cooling capacity of a particular product. Last updated Reviewed for Accuracy We have independently reviewed this article to ensure it is as accurate as possible. Check out our writing guidelines to learn more about our article creation and review process.
If an air conditioner is too powerful, it can lead to higher operating costs and uncomfortably dry air. If a window unit is too small, it can mean it breaks down quickly because it can’t keep up with the heat. Just like Goldilocks, we all want to find window air conditioning.
Choosing The Right Size Air Conditioner For Your Home
Below I have prepared a guide and calculator to help you calculate the exact power you need from a window air conditioner.
The size and power of your window air conditioner depends on the size of your room, ceiling height, amount of sunlight, people in the room, etc. must be connected. You can quickly get the correct window AC size and wattage with the guide and calculator below.
Below is our helpful visual guide followed by our free window ac size calculator. If you’re stuck on how to use it, read on for the full explanation.
Be sure to check out our guide (complete with a free calculator!) to find out how much it costs to run a window air conditioner.
How To Determine What Size Of Air Conditioner You Need
Don’t have paper and pen on hand? No problem. I have prepared a calculator that will do all the hard work for you.
It is obvious that an air conditioner that is too small will cost you more money. It will suck up all your electricity as you try to work at your maximum all day long.
Of course, a large air conditioner will be in economy mode most of the time. But the problem is that it turns on and off all the time. It opens quickly, then cools down so quickly that it shuts down again. This on/off cycle is what uses a ton of energy to start up the entire system.
Air conditioners are manufactured to maintain low temperatures and have the highest cost when they are first started. Therefore, a very large air conditioner will cost more to run.
Choosing Room Air Conditioner Capacity As Per Square Feet
Not to mention the extra wear and tear from constantly turning the compressor on and off. And the CLUNK noise every time!
Finally, a large model can cool down very quickly. So fast that the dehumidification function doesn’t work long enough and we feel cold but damp. This is extra disturbing.
If the air conditioner is too big or small, your bills will increase. It is important to size the window air conditioner correctly.

Therefore, it is important to size the window air conditioner correctly. Fortunately, this is very simple to do.
The 6 Best Air Conditioners Of 2023
Just like in the infographic, our first step is to find the base level of BTU your space needs. It just depends on the area of the room where you will place the air conditioner.
Simply multiply the length x width of a square or rectangular room to find the area. If its vertex is a right-angled triangle, then it is half the first number; because the triangle is only half of the rectangle.
If it’s more complicated than that, you’ll need to take some initiative! Divide the room into smaller sections and study each one separately. Then add it all together. There’s a little diagram in the infographic that should give you a good starting point.
Once we have a space to work in, it’s easy to get an air conditioner of equivalent size or power.
Air Condition Size Calculator (1.1.19)
Just compare it with the table below. For a good health check, multiply your space in sq ft by 25; This also gives a rough idea of the amount of BTUs we need.
See the first chart above comparing areas and BTU along with your final number. If you are stuck in the middle of two categories, I recommend you to be a little stronger.
We are very lucky with tools today. We can choose from older, cheaper models that may still work fantastically well (if you buy good ones). There are also modern models with surprising, time-saving features.
Here are some of the most popular features in a little more detail than the infographic above.
What Air Conditioner Size Do You Need? Easy Sizing Guide
Note which of these will make your life easier. You can then check the air conditioning units you’re considering to see if they have the features you need.
By using your window air conditioner correctly, you will get the best cooling from it, extending its life and keeping it quieter. You will save on energy bills while keeping your air clean.
Struggling with limited window space for your air conditioning unit? If so, you may be interested in “through-the-wall” style models or PTAC units (similar to those used in hotels).
While any window unit can be roughly fitted into a recess in the wall, some models are made specifically for this.
What Size Air Conditioner Is Right
They are slightly taller and have a more protective exterior that is easier to fit into a wall cavity. They are also slightly more effective because less cold air is lost due to the lower insulation of the window.
If you’re considering one, make sure you get an expert installation to fit it. Also make sure the location and product are what you want!
While these models are great, I highly recommend considering a ductless system instead. Instead of a large cutout, these require only a 1 or 2-inch drilled hole and a mounted bracket.
There is always a question mark between window air conditioners and portable air conditioners for those who need single-room cooling (especially renters or those living in small apartments). Let’s discuss this.
What Size Split System Do I Need?
Both types are excellent at cooling a single room. Both are easy to install (being portable)
For 8k, 10k, 12k and 14k BTU models, we looked at how many square feet each type could cool. In general, window air conditioners are more efficient per BTU than portable air conditioners.
In general, window air conditioners are noisier per BTU than portable air conditioners. This may be because portable models have more exterior walls to ensure soundproofing of the system.
We accept this as equalization of the productivity gap. For example, a 12k BTU portable computer may cost the same as a 10k BTU window; both provide the same amount of cooling.
Does Size Of Air Conditioner Matter?
Portable air conditioners are a great addition to a room, especially in a small apartment. However, window air conditioners also block about a foot of your window space! I call this about equal difficulty.
Let’s face it – window air conditioners are not nice. They’re bulky and boxy, and most of them look like they’re from the ’80s. (Although the latest models look much better). Although portable air conditioners are large, they look good and fit in as part of a modern home.
Although window air conditioners are extremely easy to install, they cannot compare to the ‘plug and play’ installation of a portable air conditioner with the right size window.
So, if you are looking for something easy to install, a portable air conditioner may be the right choice.
How To Determine What Size Air Conditioner You Need
You have no choice but to have most of your window view (and light) blocked by the air conditioner.
If you don’t own your property, you may be at the mercy of the landlord/building owner as to whether you have it or not.